JPH09165576A - Slag-based high-strength grout agent - Google Patents

Abstract

(57) [Abstract] [Problem] Strength development, durability, workability, etc. have been improved.
(EN) Provided is a grout agent used for strengthening and stabilizing the ground, which has environmental harmony without the risk of polluting the surrounding environment. A grout composition comprising granulated slag and sodium carbonate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a grout agent composition and a method of using the grout agent composition. More specifically, it relates to a suspension type grout agent composition comprising slag and sodium carbonate and a method of using the same. In the grout agent composition of the present invention, the gel formation rate can be arbitrarily adjusted from several minutes to several tens of minutes, and the strength of the solidified body after gelation exhibits high strength comparable to that of cement.

[0002]

2. Description of the Related Art A chemical injection method using a grouting agent (a grouting method) is widely used for the purpose of strengthening and stabilizing soft ground. So far, various grout agents (ground injection chemicals) and construction methods have been proposed and put to practical use. In either case, the grout agent is required to have various properties such as strength after curing, ease of preparation of gel time, permeability into the ground, and environmental impact.

Currently, the most widely used is a grouting agent containing water glass as a main component. Calcium compounds such as cement, lime and slag are already known as the hardening agent. For example, in Japanese Patent Laid-Open No. 7-166163, Si
A grout agent containing water glass and fine particle slag as an active ingredient in which the O ₂ / Na ₂ O molar ratio is in the range of 1.5 to 2.8 is disclosed. Further, as a hardening agent for water glass, inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid and salts thereof or glyoxal,
Ethylene carbonate and the like are already known and have been put to practical use.

Generally, most of the water-glass type grouting agents have a problem that the alkaline component and the silicic acid component are leached into the groundwater even after the solidification, and the solidification strength decreases with time. Therefore, it is generally used as a ground injection solidifying agent for short-term temporary construction, and is not suitable for long-term temporary construction or permanent ground improvement.

In order to solve the problem of strength reduction due to the elution of alkali components and silicic acid components, for example, JP-A-59-15 is used.
No. 2984 and JP-A-59-152985 disclose a silica sol-based grout agent which can reduce the elution of alkaline components into groundwater without using water glass.
However, these grout agents generally have low caking strength, and are regarded as temporary or temporary soil stabilizing agents for a relatively short period of several weeks to a month.

On the other hand, as a grout agent having a high strength of a solidified body, a suspension type grout agent mainly composed of cement is already known. For example, it is a technique represented by JP-A-1-133965. However, it is known that the general-purpose cement has a relatively large primary particle size and thus has insufficient permeability to the ground. In recent years, a method using ultrafine particle cement has been proposed, but there is a problem in that the fine particle cement is inferior in productivity, is produced in a small amount, and is expensive.

[0007] On the other hand, a method is known in which a high molecular weight agent represented by acrylic amide, an aqueous urea resin or the like is used as a grout agent for ground stabilization, but the human body is caused by the outflow of uncured components into groundwater. The fact is that there is a concern about the impact on the product and its use is strictly limited. In recent years Heisei 7
After the Great Hanshin Earthquake that occurred in January, 2011, a high-strength or high-strength grout agent was used to prevent seismic disasters of important structures built or about to be built on soft ground around the city. The necessity of the construction method is strongly demanded.

As a grouting agent which is said to be richer in strength than a water glass type or silica sol type grouting agent, a grouting agent mainly composed of slag such as blast furnace slag and converter slag is
For example, Japanese Unexamined Patent Publication No. 6-219796 and Japanese Unexamined Patent Publication No. 6-2285.
No. 58 and Japanese Patent Application Laid-Open No. 7-119138. In these disclosed techniques, a relatively strong solidified body is obtained by adding an alkaline solution such as a water glass solution or a sodium aluminate solution to slag, but most of them are solidified bodies. Uniaxial compressive strength of tens of Kgf / cm ²
There is a demand for even higher strength. Furthermore, in the known technology regarding slag-based grout agents up to now, most of the slag hardener components are basically aqueous solutions, and they are blended with dry slag in advance and packaged in one pack.
Since it could not be supplied, it was necessary to separately measure, mix, and disperse each at the injection site, and there was a risk of complexity and measurement error. That is, typical 1-3
Since water glass and sodium aluminate solution decompose or deteriorate in the solid state, dry blending with slag particles has not been realized so far. In addition, the slag-based homogel solids and the like obtained by such a technique often have a so-called self-disintegration phenomenon in which cracks generally occur due to repeated drying and wetting. This phenomenon is a big problem from the viewpoint of durability, and improvement is strongly demanded. It is clear that the grouting agent, which can be adjusted in a wider range with respect to the gel time, is excellent in construction management, and in recent years, a new grouting agent capable of solving the above-mentioned problems has been particularly demanded.

[0009]

The object of the present invention is to provide a high-strength, high-strength material that has excellent permeability to various types of ground, has a rapid rise in the setting strength after gelation, and can be used in a few days for practical strength. It is to provide a grout agent. Another object of the present invention is to provide a novel slag-based suspension type grout agent in which the solidified body is highly permanent and does not cause problems such as self-disintegration phenomenon. Still another object of the present invention is to dry-blend a predetermined amount of the active ingredients of the grout drug in advance.
The purpose of the present invention is to provide a grouting agent that exhibits high reliability by reducing miscompounding and complexity of drug preparation by making it possible to pack and supply. Still another object of the present invention is to provide a method for strengthening and stabilizing soil-unstable soil typified by soft soil and rock cracks, which uses the chemical.

[0010]

Means for Solving the Problems As a result of intensive studies to overcome the above-mentioned problems, the present inventor has found that by adding sodium carbonate to granulated slag, slag particles that are not self-hardening gradually and Stable gelation and solidification within a certain period of time, formation of a strong solidified body that compares favorably with a hardened body composed mainly of cement with similar suspension components, and self-disintegration phenomenon It was also confirmed that the solidified body is a solidified body having the same crystal structure as the cemented solidified body, and it was concluded that the solidified body is a grout agent satisfying the above-mentioned problems. The invention was completed.

That is, the present invention is a grout agent composition containing 100 to 1,500 kg of granulated slag per 1 m ³ , 20 to 200 kg of sodium carbonate as a hardening agent, and water and having excellent strength development and penetrability. Is. Further, the present invention is a method for press-fitting the above grout agent with one liquid into an unstable ground or a rock crack gap in the ground through a grout injection pipe to solidify the grout agent to strengthen and stabilize the ground or the rock, , Double-phase injection through a double-pipe type grout injection pipe, a method for strengthening and stabilizing the ground and rock, and the grout agent for the continuous gap in the ground made by super-high-pressure water discharge A method for constructing a continuous underground pile or a continuous underground wall, which is characterized in that it is used as an injection agent for a jet grout method in which it is press-fitted through and solidified.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The grout agent of the present invention is basically a suspension type grout agent composed of granulated slag and sodium carbonate. As for its performance, high strength and high durability are the most important characteristics, and as a suspension type, it cures quickly,
It can be said that the gel time can be achieved even in a region of a few minutes, which is so-called "Nakatsuki". This enables application to the multi-phase injection method.

The granulated slag of the present invention is preferably a granulated slag of a metal smelting by-product represented by blast furnace granulated slag, converter granulated slag, electric furnace granulated slag, open hearth granulated slag and the like. To be More preferably, the SiO ₂ content is 30 to 35% by weight, the CaO content is 35 to 45% by weight, the Al ₂ O ₃ content is 13 to 20% by weight, the MgO component is 5 to 8% by weight, and other components are several weight%. Granulated blast furnace slag composed of various composition ratios such as containing 0.1% can be mentioned.

As the slag, metal smelting slow cooling slag is excluded from the present invention. The reason is that the slowly cooled slags are crystalline slags and have no latent hardenability. However, a small amount of crystalline component may be mixed in the granulated slag component of the present invention, and basically, the amorphous slag obtained by the so-called water slag method of water cooling method can be preferably used. .

Generally, granulated slag (also referred to as water sludge slag, hereinafter simply referred to as slag) does not exhibit self-hardening by itself. However, in an aqueous solution in the presence of an alkali or in a high humidity environment, SiO ₂ and Al ₂ O ₃ components elute and then Ca
Ions are eluted and calcium silicate hydrate crystal gel is generated on the surface of the slag particles, etc., and the particles are gradually solidified and gelated, and finally a solidified body is obtained by solidifying with time, It is well known that the strength of the solidified body increases with time. In that case, if the amount of alkali used is too small, no integral gelation occurs, or if it is too large, the slurry viscosity is too high and the fluidity is poor and pumping is not possible, or the viscosity changes significantly. Therefore, it is a general fact that the ground injection is interrupted or cannot be performed at all, and the case of sodium carbonate which is the alkali curing agent component of the present invention is no exception.

The preferred particle size distribution of the slag that can be used in the present invention is that it has a Blaine value of 3,000 cm ² / g or more (a value representing a specific surface area per g) and a maximum particle size of 250 μm or less. The Blaine value is preferably 5,000 cm ² / g or more, and more preferably the Blaine value is 8,000 cm ² / g or more because of the following reasons.

The Blaine value of the coarsely crushed product is 3,000 to
Although it is possible to form a high-strength solidified body basically by using a material in the range of 5,000 cm ² / g, the soil permeability is poor,
It is not suitable as a slag for pouring into the ground. However,
It can be used as a slag for a grout injection agent for a jet grout method without any problem. Therefore, from the viewpoint of completely ensuring the soil permeability, the slag for grout agent of the present invention preferably has a Blaine value of 8,000 cm ² / g or more, and about 10,000 cm ² / g. Is more preferable. Although the upper limit of the Blaine value is not particularly limited, it is usually 30,000 cm ² / g in terms of production.

The amount of the slag in the grout agent of the present invention is 100 to 1,500 kg per 1 m ^{3 of the} total amount of grout.
Range. The range is preferably 200 to 1,000 kg, and more preferably 300 to 800 kg. Slag content is 100 per 1 m ^{3 of} total grout
If it is less than kg, not only is it difficult to gel within a few hours, but also the setting is slow and the final solidified product has poor practical strength. On the other hand, the slag content is 1 total grout.
This is because if it exceeds 1,500 kg per m ³ , the viscosity of the suspension solution becomes too high, and the fluidity and the injection workability are poor.

The alkaline agent used as the curing agent is sodium carbonate. The sodium carbonate may contain potassium carbonate or potassium bicarbonate. Alternatively, the second and / or third alkali metal phosphate may be contained in place of potassium carbonate. Further, it may contain a small amount of sodium bicarbonate, and it can be preferably used if the proportion of bicarbonate in the components is less than 10% by weight. Sodium carbonate may be solid or may be mixed in an aqueous solution. When potassium carbonate or potassium bicarbonate is added, each of these components may be individually weighed and mixed with the slag. The same applies when the second and / or the third alkali metal phosphate is added.

When sodium carbonate is added and blended as an aqueous solution, it is important to set the pH of the aqueous solution to 11.5 or more, more preferably 12 or more. Further, an aqueous solution in which potassium carbonate or potassium bicarbonate is appropriately blended or an aqueous solution in which second and / or third alkali metal phosphates are suitably blended so as to have a pH of 11.5 or higher can be a preferable curing agent component of the present invention. However, in general, when an excessive amount of the phosphate or alkali bicarbonate is added to the curing agent component, the pH value of the resulting curing agent aqueous solution often becomes 11.5 or less. Further, even if the amount of alkali bicarbonate is increased by absorbing carbon dioxide gas in the air more than necessary in the once obtained hardener aqueous solution having a pH of 11.5 or more, the pH value is 1 or less.
It may be less than 1.5, so be careful. In the grout agent composition when the pH value of the curing agent aqueous solution is 11.5 or less, the latent curing property of the slag is not sufficiently drawn out, and sufficient gelation or coagulation is not completed even after at least 24 hours at room temperature. Therefore, it cannot be said to be a preferable curing agent of the present invention.

The amount of sodium carbonate is 1 m of total grout.
It is in the range of 20 to 200 kg per ³ , preferably 50
~ 200 kg range, more preferably 100-200 k
g. This is because if the compounding amount is less than 20 kg, the grout consolidation strength is low and the durability is lacking.
This is because if the amount exceeds kg, not only a remarkable effect cannot be found even if the amount is further increased, but also the cost becomes high.

In the present invention, there is no problem in using potassium carbonate together with sodium carbonate for the purpose of adjusting gel time and stabilizing liquid viscosity. For the same purpose, second and / or third alkali metal carbonates may be used in combination. By using these in combination, it becomes possible to maintain the liquid viscosity immediately after compounding in a relatively low region. However, even if only sodium carbonate is used, the liquid viscosity is not so large as to impede the permeation injection. The amount of potassium carbonate added is preferably in a range not exceeding the amount of sodium carbonate added. This is because even if the amount of sodium carbonate added is exceeded, the cost becomes high and the gel time becomes longer than necessary, which is not effective.

When the second and / or third alkali metal phosphates are blended, it is important to keep the content ratio to a very small amount. The reason is that the phosphate salt is presumed to act as a hardening aid that delays the hydration hardening property of the slag, so that the gel time can be adjusted arbitrarily by the content ratio. The addition amount of the phosphate expressed in terms of solid content is within the range of not more than 5 kg per 1 m ^{3 of the} total amount of grout. It should be noted that if more than 5 kg is added, the hardenability of the slag may be significantly impaired. When preparing a relatively short gel time, the total amount of grout per 1 m ³ is preferably 0.05 to
It is in the range of 3 kg, more preferably in the range of 0.1 to 1 kg. By blending about 0.05 to 0.1 kg per 1 m ^{3 of the} total amount of grout, the gelling behavior of a low viscosity of several minutes can be realized. Further, gelling and setting behavior of several tens of units can be realized by compounding about ^{3 to 5} kg per 1 m ^{3 of the} total amount of grout.

In the grout composition of the present invention, sodium carbonate not only brings out the latent hydraulic property of the slag,
As a very characteristic feature, the following basic grout suitability and the like can be sufficiently satisfied, and it is an important essential component of the present invention. First, the initial viscosity of the slag-alkaline water suspension can be set to a low viscosity that can be infiltrated into the ground. Secondly, as a result, the injection pressure to the ground or the like can be set low and high-speed injection becomes possible. Thirdly, the gelation / caking time can be adjusted easily and stably with good reproducibility from a few minutes to a few tens of minutes, and practical strength is developed within a few days after gelation (it becomes a fast-strength grout agent). . Fourthly, the solidified body has high strength characteristics equal to or higher than the cemented solidified body mixed with water in the same amount as slag, and is stable to repeated dry-wet cycles and durable. It becomes a slag-based consolidated gel rich in. Fifth, sodium carbonate can be dry blended with slag,
The mixed powder composition is stable for a long period of time and can be supplied to the grout injection site in one pack. Therefore, it is possible to easily establish a supply system in a form that completely matches the demand of any grout injection maker in advance, avoid complications at the site, eliminate mixing mistakes, and as a result, the grout agent of the present invention The setting reliability and injection work stability are secured.

In addition to the above components, a colloidal silica solution stabilized in the alkaline region may be added to the grout agent of the present invention. In the grout agent composition of the present invention to which the colloidal silica solution is added, special liquid stability can be secured. That is, the uniform stability of the system in a so-called stationary state after kneading and stirring at the time of blending is significantly improved.

As the colloidal silica solution, a product obtained by a known method may be used. Generally, after removing the alkali content in the alkaline water glass solution with an ion exchange resin to generate ultra-micro size silica gel particles of 10 to 30 mμ in the solution, it is possible to re-use caustic soda or caustic potassium again. A product obtained by a method of adding a trace amount of an alkaline component to ensure long-term storage stability is common and can be preferably used. More specifically, as a colloidal silica solution, it is 5 to 5 in terms of solid content of the active ingredient represented by SiO _2.
A 50% by weight solution can be used. Grout total 1m ³
Therefore, it is preferable that the amount of the aqueous solution is 20 to 250 kg, more preferably 50 to 100 kg, which is 10 to 30% by weight in terms of the solid content of the active ingredient represented by SiO ₂ .

As already clear from many documents, colloidal silica itself basically has a gelling ability like a water glass solution. Therefore, when it is used as a grouting agent component of the present invention, the grouting agent is not used. Does not adversely affect workability and solid physical properties. That is, in the grout agent of the present invention, a suspension-type grout agent composition containing the slag, sodium carbonate, and the colloidal silica as an active ingredient of the grout agent having one solution and tens of minutes gel time, It is a more preferable embodiment of the present invention because it has a low viscosity and is superior in the long-term stability of a statically injected liquid drug.

Further, in the grout agent of the present invention, in addition to the above-mentioned active ingredients, the following known cement additives, known hydraulic inorganic fine particles other than slag, known non-hydraulic inorganic fine particles, known publicly The above-mentioned surfactants and the like may be used in combination within the range that meets the purpose of the present invention.

The known additives for cement include, specifically, setting accelerator for cement, setting retarder for cement, water reducing agent for cement, agent for reducing sedimentation and separation of organic cement particles, and preferably cement among them. It is preferable to use one or more selected from the group consisting of a setting accelerator for cement, a setting retarder for cement, and a water reducing agent for cement. These cement additives may be used in a range of up to less than 50 kg per 1 m ^{3 of the} total amount of grout, preferably less than 30 kg in a commercially available form.

Preferred setting accelerators for cement which can be used together as the grout agent component of the present invention include alkali metal or alkaline earth metal oxides, chlorides, sulfates, nitrates and other alkaline earth metal carbonates. The hydroxide etc. are mentioned. Similarly, examples of the setting retarder for cement that can be used in combination with the present invention include inorganic acids such as phosphoric acid and boric acid, organic acids such as citric acid and gluconic acid, and sugars such as sucrose, granulated sugar and glucose. . Similarly, examples of the cement water-reducing agent that can be used in combination in the present invention include various known organic cement water-reducing agents such as melamine-based water reducing agents, naphthalene-based water reducing agents, and lignin-based water reducing agents. Similarly, examples of organic cement particle sedimentation / separation reducing agents that can be used in combination with the present invention include methyl cellulose, hydroxy cellulose, soluble starch, polyvinyl alcohol and the like. Similarly, hydraulic inorganic fine particles other than known slag that can be used together in the present invention, clay represented by bentonite, amorphous fine alumina powder, fine cement powder, hemihydrate gypsum powder, anhydrous gypsum powder, Examples include activated clay powder and orthosilicate glass powder.
Similarly, known non-hydraulic inorganic fine particles that can be used together in the present invention include crystalline fine silica, crystalline fine alumina,
Examples include calcium carbonate powder, titanium white powder, red iron oxide, and talc powder. Further, similarly, known surfactants that can be used together in the present invention include anion soap, cation soap, nonion soap and the like.

It was confirmed in advance that the hydraulic inorganic fine particles other than the above-mentioned known slag, known non-hydraulic inorganic fine particles, known surfactants, etc. do not adversely affect the basic performance of the grout agent of the present invention. It is essential that the grouting agent of the present invention be used in combination with the grouting agent of the present invention within a range that does not interfere with basic performance.

The grouting agent of the present invention containing slag and sodium carbonate and optionally a colloidal silica component in combination may be basically used as one liquid or two liquids without any particular limitation. . When the curing time of the grout agent is short, such as several minutes to about 20 minutes, usually two solutions are used, and the grout agent composition can be formed by a method such as mixing at the tip of the injection tube or mixing immediately before the injection tube. There is no particular restriction on the form of the two liquids, but in general, a suspension composed of slag and water is used as the main liquid, and the other hardener liquid is a sodium carbonate solution, and if necessary, a colloidal silica solution. It is possible to preferably employ a method in which one or both of them are contained. In addition, for example, a suspension containing slag, water, and a small amount of sodium carbonate component as the main agent liquid,
It is also preferable to use the other curing agent solution as the remaining aqueous solution of sodium carbonate.

When the curing time of the grout agent is long, about 30 minutes to 1 hour, usually one solution is used, and a method of press-fitting and discharging the grout agent composition from a single injection tube can be preferably adopted. There is no particular limitation on the pre-blending form of the one-pack type grout agent, and a predetermined amount of solid slag powder and sodium carbonate powder are dry-blended in advance and transported, and after opening at the ground injection site, a predetermined amount of water is added. A preparation method such as dispersion-dissolving and mixing can be preferably adopted.

As a ground stabilization method using the one- or two-liquid type grout agent of the present invention prepared as described above, generally, ground injection is carried out through a ground injection pipe which is buried in advance. However, a construction method for stabilizing the unstable ground is preferable. In particular, the grout agent of the present invention is prepared as one liquefaction,
A method of press-fitting and solidifying the ground and rock crack gaps in the ground through the grout injection pipe to solidify the ground and rock is preferable because the injection work is simple.

Further, a method of injecting the grout agent of the present invention in multiple phases through a double-tube type grout injection tube to strengthen and stabilize the ground or rock is also a preferable method. Furthermore, it is possible to use the grouting agent of the invention as a grouting agent for a method of constructing a continuous underground pile or a continuous underground wall. Specifically, it is press-fitted through a grout injection pipe into a continuous gap in the ground formed by discharging water at an ultrahigh pressure to solidify it.
The above-mentioned grout agent composition of the present invention can be used as an injection agent for a so-called jet grout method, and can be solidified, and as a result, a continuous underground pile or a continuous underground wall can be constructed.

When stabilizing the ground, two or three types of known water-glass type complete solution type long-duration hardening type agents for about 30 minutes to 1 hour and the relatively short-time hardening type grout agent of the present invention are used. By injecting two or more grout agents in multiple phases, it is possible to achieve emergency water stoppage and high-strength, low-cost ground improvement. Therefore, the double-phase repeated injection method with other known grout agents is also included in the grout injection method of the present invention.

[0037]

EXAMPLES Examples, comparative examples and construction examples of the present invention will be shown below, but the present invention is not limited thereto. Also,
% And parts in the examples mean% by weight and parts by weight, respectively.

[Materials used] 1. Slag Commercially available granulated blast furnace slag (trade name: Fine Cementment)
It was used. However, the Blaine value is a measured Blaine value obtained by the cell ventilation method specified by the Concrete Association. The type of slag and the result of the Blaine value are shown in Table 1 below.

[0039]

[Table 1]

2. Curing liquid (sodium carbonate aqueous solution) Aqueous solutions (Nos. 1 to 5) having the formulations shown in Table 2 below were prepared and used. Among them, No. For No. 5, pH was adjusted to 11 by adding phosphoric acid to an aqueous solution containing the main components. N
o. 6 is a powder of sodium carbonate.

[0041]

[Table 2]

3. Colloidal silica solution A commercially available product (trade name: cataloid) was used. The solution is S
The active ingredient concentration of iO ₂ is 30%, and the pH value is 9.5.
The primary silica gel particle size is 20 mμ. 4. Additives Calcium carbonate (No. 1) and citric acid (No. 2) as reagents were used. 5. Cement water reducing agent A product of Mitsui Toatsu Chemical Co., Ltd .: Melflow 40, which is one type of melamine water reducing agent, was used. 6. Water glass solution A commercially available No. 1 water glass solution was used as it was.

Example 1 500 g of the curing liquid No. 1 was added to 5 parts at the ratio shown in Table 3 below.
The mixture was placed in an L capacity compounding container, 500 g of No. 2 slag was added under strong stirring, and 3 minutes after addition and mixing, city water was added to make 1 L, and the mixture was stirred and mixed for 1 minute. The thus obtained grout agent in the form of a suspension solution of Example 1 was evaluated by the following method.

The gel time is measured as an elapsed time from the time when the addition of slag to the curable liquid is completed as a starting point to the time when it is determined that the prepared compounded liquid is tilted from the stationary state to lose the mobility. , Shown in Table-4.

As for the permeability, the liquid 50 immediately after completion of stirring was filled with Toyoura standard sand in a transparent acrylic cylindrical container (diameter 50 mm, length 1 m) so that the filling height was 50 cm in advance.
0 mL from the top of the Toyoura standard sand layer through a porous shielding guide plate with a hole diameter of about 1 mm, and an osmotic pressure of 1 kgf / c.
It was measured by permeation under a constant pressure of m ² .
When permeating into the gaps between standard sand particles, the state that the permeation layer gradually becomes opaque with the cloudy suspension color of the slag itself toward the bottom is observed by visual observation from the outside. A judgment was made, and the case where the entire standard sand layer filling area was visually observed in the above state was judged to be good permeability (pass). The results are shown in Table-4.

The syneresis, uniaxial compressive strength and self-disintegrating property were evaluated as follows. Immediately after the completion of the stirring, the mixture was filled into a mold (50 mmφ × 100 mm), and the mold was removed one day later. The amount of syneresis water generated at this time was measured, and the volume ratio to the cured product was calculated and evaluated in four steps. After the obtained homogel was cured in water for 7 days, it was subjected to measurement of uniaxial compressive strength. The crosshead speed at this time was 1 mm / min. The results are shown in Table-4.

The presence or absence of self-disintegrating property depends on the mold (50 mm
The homogel demolded from (φ × 100 mm) after 5 days of curing and curing was immersed in city water for 1 hour to wipe off water on the surface, and then left in the air for 1 hour. Repeat this operation 5 times,
Visual observation was carried out, and when no crack was observed at all, it was judged as having no self-disintegrating property (pass). The results are shown in Table
It was described in 4.

Permanence evaluation was carried out by the following method.
The formulation liquid prepared according to Table-3 and Toyoura standard sand were mixed at a weight ratio of 1: 4, and molded (50 mmφ × 100 mm).
The sand gel obtained by demolding after 1 day.
After underwater curing for 1 day, 3 months, 6 months, 12 months,
Permanence was evaluated by measuring uniaxial compressive strength. The results are summarized in Table-5.

Examples 2 to 20 According to the formulations shown in Table 3, a formulation liquid was prepared in the same manner as in Example 1 and the physical properties were evaluated. The colloidal silica, additives, and water-reducing agent in Example 11 and below are blended subsequently to the curing liquid and water, and finally slag is blended to obtain a predetermined blended liquid.
The results are summarized in Table 4. Regarding the durability evaluation, the same method as in Example 1 was performed for Examples 3, 5, 13, and 18. The results are summarized in Table-5.

Example 21 Polystyrene-aluminum laminated type, content 100
Prepare a 0 mL pack bag, and add sodium carbonate powder (curing agent No. 6) so that the amount of active ingredient is the same as in Example 1.
Of 125 g and 500 g of slag (No. 3) were dry blended and loaded into the pack bag to prepare a dry mix pack. After storing at room temperature for 1 month, the bag was opened, and the total amount of the content and the required amount of city water were added to 1 L and stirred. Using the liquid medicine thus prepared, the same physical property evaluation and permanence evaluation as described above were carried out. As a result, the same result as that of Example 1 was obtained.

Reference Examples 1 to 3 and Comparative Examples 1 to 9 Formulation liquids were prepared in the same manner as in Examples according to the formulations shown in Table-3.
Physical properties were evaluated. The results are summarized in Table 4.

Comparative Examples 10 and 11 According to the formulations shown in Table 3, a liquid mixture containing water glass and slag was prepared, and the physical properties were evaluated in the same manner as other comparative examples. The results are summarized in Table 4.

Construction Example 1 Regarding the above Examples 1 and 13, a construction test (grouting suitability) was conducted on the actual ground. Using a grout machine, the mixed solution was injected into the ground at a pressure of ² kgf / cm ² , and was permeated into a range of approximately 1 m in diameter and 3 m in depth. After digging out 7 days later and observing each part, a uniform infiltrated solid was formed at any part. No cracks or remarkable volume shrinkage were observed, and no alkaline contamination of the surrounding soil was observed.

Construction Example 2 Regarding the above Examples 1 and 13, a construction test (jet grout suitability) was carried out on the actual ground. By jetting water at an extremely high pressure (500 kgf / cm ² ), jet grouting holes (diameter 1.5 m × depth 3 m) were opened in the ground at intervals of about 1 m, and the blended liquid was pressed into the continuous gap created thereby. Ten days later, when the surrounding area was dug up, a continuous wall was built over the entire press-fitting area. No cracks or remarkable volume shrinkage were observed in each part, and no alkaline contamination of the surrounding soil was observed.

Construction Example 3 For the above Reference Examples 1 and 2, a construction test (suitability for jet grout) was carried out on the actual ground in the same manner as in Construction Example 2. Slag not suitable for permeation injection (No.
Although 1) was used, the jet grout suitability was good, and press-fitting was possible without any difference from the case of construction example 2. Ten days later, when the surrounding area was dug up, a continuous wall was built over the entire press-fitting area. No cracks or remarkable volume shrinkage were observed in each part, and no alkaline contamination of the surrounding soil was observed.

[0056]

[Table 3]

[0057]

[Table 4] -In each case, water is added to the above mixture to make 1 L.

[0058]

[Table 5]

[0059]

[Table 6] (Explanation of symbols in Table-4) [Penetration] ○: Permeation into standard sand [Servaged water] ◎: 0.1% or less ×: Impermeability into standard sand ○: 1% or less [Self-disintegration] ○: Not visible to the naked eye Δ: 5% or less ×: Appearable to the naked eye ×: 5% or more

[0060]

[Table 7]

[0061]

From the above-mentioned evaluation results of physical properties (Table 4), in Examples 1 to 21, the gel time was about 5 to 70.
As a result, the result that the uniaxial compressive strength was 150 kgf / cm ² or more was obtained. Since neither has a problem in permeability, it is suitable as an example of the present invention. From the results of Examples 1 to 6, in the basic composition in which the slag and the curable liquid are compounded in the same weight, if the materials and the compounding ratio are within the scope of the present invention, good properties can be obtained by combining only the slag and the curable liquid. It is shown that a grouting agent can be created. Of these, in Examples 1 to 4, when a curing liquid within the scope of the present invention was used,
It is shown that good properties can be maintained, and in Examples 5 and 6 the same is shown for the combination with the slag having a larger specific surface area. In addition, Examples 7 to 1
At 0, it is shown that good properties are retained even by changing the blending amount of slag within the range of the present invention.

On the other hand, Examples 11 to 20 are examples in which calcium carbonate, citric acid, colloidal silica, melamine water reducing agent, etc. are used as additives, but the effects of the present invention are not impaired and the setting time and strength are adjusted. It was found to have effects such as enhancement. Among them, in Examples 11 and 12, strength enhancement and gel time shortening were achieved by adding calcium carbonate and increasing the amount of the hardening liquid, and even in the system in which colloidal silica was added as in Examples 14 and 16, the same as above. The effect is recognized. In Examples 15 and 17, the gel time extension by the addition of citric acid was achieved. As seen in Examples 13 to 17 and 20, the addition of colloidal silica did not cause a decrease in strength or the like, and showed an effect of improving stability. It was also possible to add water reducing agents as seen in Examples 18 and 19. In Example 20, the gel time shortening effect by increasing the amount of colloidal silica is observed.
Furthermore, Example 21 is a case in which the essential component of the present invention was used as a dry pack and then stored for a certain period of time, but it was shown that exactly the same results as in the case of being produced by a normal method can be obtained, It was found that the main ingredient slag and the hardening agent sodium carbonate can be supplied in one pack.

As compared with the above-mentioned examples, when slags that were not made into fine particles were used as in Reference Examples 1 to 3, the slag was hardened, but the permeability was not sufficient when permeation injection was envisioned. As shown in FIG. 3, it is applicable only to the jet grout method. Regarding the pH of the curing liquid, when it is lower than pH 11.5 as in Comparative Example 1, curing is significantly delayed, which is not preferable. When the blending amount of sodium carbonate exceeds the upper limit as in Comparative Examples 2 and 3, the gel time is remarkably shortened and the initial viscosity is increased, so that the permeability is not sufficient. On the other hand, when the blending amount of sodium carbonate is below the lower limit as in Comparative Examples 4 and 5, curing is not observed within at least 24 hours.

Also, as in Comparative Examples 6 and 7, when the amount of slag is too small with respect to the amount of water mixed, at least 2
No hardening was observed within 4 hours, which is not consistent with the spirit of the invention. On the other hand, when the amount of slag is too large with respect to the amount of water blended as in Comparative Examples 8 and 9, the paste becomes a paste from the initial stage of blending and the permeability is remarkably poor. Furthermore, as in Comparative Examples 10 and 11, in the conventional slag-based grouting agent using water glass, the uniaxial compressive strength is not as high as that of Examples, and a self-disintegration phenomenon is also observed, which is not preferable as a permanent grout. . On the other hand, from the above-mentioned durability evaluation results (Table-5), high strength was developed early after 3 days in any combination,
Moreover, the change over time is in the direction of increasing the strength. It is presumed that this is because the hydration / condensation of the unhydrated particles proceed rapidly in an early stage, but no self-disintegration phenomenon is observed and permanent strength retention is observed. Further, as shown in Construction Examples 1 and 2, the grout agent of the present invention has workability sufficient to be constructed by ordinary grout equipment, and can form good reinforced ground or continuous underground wall. .

Summarizing the above results, the use of the slag of the present invention and the grout agent containing sodium carbonate and water as the main components is remarkable in the following points. 1. It has a crystal structure similar to that of hardened cement, and can achieve a compressive strength of 150 kgf / cm ² or more, which was hardly achieved in the past, in a few days. 2. It also has good durability and gives highly reliable solids without self-destruction. 3. By limiting the particle size of the slag, the permeability to the soil is improved, and it can be applied to the infiltration injection method for almost all ground. The jet grout method can be applied regardless of the particle size of the slag. 4. The gel time can be easily adjusted, and an appropriate gel time can be selected depending on the construction case. 5. It is possible to provide an environment-friendly grout agent that does not contain dangerous substances or substances harmful to the human body and has no contamination of groundwater or the like.

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Claims (12)

[Claims] 1. Granulated slag of 100 to 1 per 1 m ³
500 kg, 20 to 20 sodium carbonate as a curing agent
A grout agent composition containing 0 kg and water and having excellent strength development and permeability. 2. The granulated slag has a Blaine value of 8,000 cm.
The grout agent composition according to claim 1, which is a fine particle slag having a content of ² / g or more. 3. The grout agent composition according to claim 1 or 2, wherein the granulated slag is granulated blast furnace slag. 4. The sodium carbonate is composed of an aqueous solution and has a pH of 11.5 or higher.
4. The grout agent composition according to any one of 3 above. 5. The grout agent composition according to claim 1, wherein the potassium carbonate is contained in a range not exceeding the amount of sodium carbonate blended. 6. The method according to any one of claims 1 to 4, wherein the second or third alkali metal phosphate is contained in a range of 0.01 to 5 kg in terms of solid content per 1 m ^{3 of the} total amount of grout. The grout agent composition as described in 1 above. 7. A silica concentration of 5 to 50 having a pH of 8 or more.
The grout agent composition according to any one of claims 1 to 6, which contains a colloidal silica aqueous solution containing 20 wt% in terms of silica solid content in an amount of 20 to 250 kg per 1 m ^{3 of the} total grout. 8. The method according to claim 1, further comprising one or more selected from a setting accelerator for cement, a setting retarder for cement and a water reducing agent for cement, in an amount of 50 kg or less per 1 m ^{3 of the} total amount of grout. The grout agent composition according to claim 1. 9. A grout composition comprising 100 to 1,500 parts by weight of granulated slag and 20 to 200 parts by weight of sodium carbonate. 10. The grout agent according to any one of claims 1 to 8 is press-fitted into one of the liquids through a grout injection pipe into an unstable ground or a rock crack gap to be solidified, A method of strengthening and stabilizing the ground and rock. 11. A method of strengthening and stabilizing the ground or rock by injecting the grouting agent according to claim 1 in a multiple phase through a double-tube type grouting injection pipe. 12. The grout agent according to any one of claims 1 to 8 is press-fitted through a grout injection pipe into a continuous gap in the ground formed by discharging water at an ultrahigh pressure to solidify the grout agent. A method for constructing a continuous underground pile or a continuous underground wall, which is used as an injection agent for a jet grout method.